8718181920 has 576 divisors, whose sum is σ = 36560160000. Its totient is φ = 1885814784.

The previous prime is 8718181919. The next prime is 8718181921. The reversal of 8718181920 is 291818178.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (8718181919) and next prime (8718181921).

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (8718181921) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 9384016 + ... + 9384944.

It is an arithmetic number, because the mean of its divisors is an integer number (63472500).

Almost surely, 2^8718181920 is an apocalyptic number.

8718181920 is a gapful number since it is divisible by the number (80) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 8718181920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (18280080000).

8718181920 is an abundant number, since it is smaller than the sum of its proper divisors (27841978080).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

8718181920 is a wasteful number, since it uses less digits than its factorization.

8718181920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 990 (or 965 counting only the distinct ones).

The product of its (nonzero) digits is 64512, while the sum is 45.

The square root of 8718181920 is about 93371.2049831210. The cubic root of 8718181920 is about 2058.1418755446.

The spelling of 8718181920 in words is "eight billion, seven hundred eighteen million, one hundred eighty-one thousand, nine hundred twenty".